git/sha1/openssl.h
Taylor Blau 4c61a1d040 sha1: do not redefine platform_SHA_CTX and friends
Our in-tree SHA-1 wrappers all define platform_SHA_CTX and related
macros to point at the opaque "context" type, init, update, and similar
functions for each specific implementation.

In hash.h, we use these platform_ variables to set up the function
pointers for, e.g., the_hash_algo->init_fn(), etc.

But while these header files have a header-specific macro that prevents
them declaring their structs / functions multiple times, they
unconditionally define the platform variables, making it impossible to
load multiple SHA-1 implementations at once.

As a prerequisite for loading a separate SHA-1 implementation for
non-cryptographic uses, only define the platform_ variables if they have
not already been defined.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-27 11:27:47 -07:00

51 lines
1.2 KiB
C

/* wrappers for the EVP API of OpenSSL 3+ */
#ifndef SHA1_OPENSSL_H
#define SHA1_OPENSSL_H
#include <openssl/evp.h>
struct openssl_SHA1_CTX {
EVP_MD_CTX *ectx;
};
typedef struct openssl_SHA1_CTX openssl_SHA1_CTX;
static inline void openssl_SHA1_Init(struct openssl_SHA1_CTX *ctx)
{
const EVP_MD *type = EVP_sha1();
ctx->ectx = EVP_MD_CTX_new();
if (!ctx->ectx)
die("EVP_MD_CTX_new: out of memory");
EVP_DigestInit_ex(ctx->ectx, type, NULL);
}
static inline void openssl_SHA1_Update(struct openssl_SHA1_CTX *ctx,
const void *data,
size_t len)
{
EVP_DigestUpdate(ctx->ectx, data, len);
}
static inline void openssl_SHA1_Final(unsigned char *digest,
struct openssl_SHA1_CTX *ctx)
{
EVP_DigestFinal_ex(ctx->ectx, digest, NULL);
EVP_MD_CTX_free(ctx->ectx);
}
static inline void openssl_SHA1_Clone(struct openssl_SHA1_CTX *dst,
const struct openssl_SHA1_CTX *src)
{
EVP_MD_CTX_copy_ex(dst->ectx, src->ectx);
}
#ifndef platform_SHA_CTX
#define platform_SHA_CTX openssl_SHA1_CTX
#define platform_SHA1_Init openssl_SHA1_Init
#define platform_SHA1_Clone openssl_SHA1_Clone
#define platform_SHA1_Update openssl_SHA1_Update
#define platform_SHA1_Final openssl_SHA1_Final
#endif
#endif /* SHA1_OPENSSL_H */